This invention relates to compositions comprising arylene sulfide polymers. In one aspect, this invention relates to compositions comprising arylene sulfide polymers and additives, which enhance the impact strength of the polymers. In other aspects, this invention relates to methods of blending suitable additives with arylene sulfide polymers in sufficient quantity to improve impact strength of the arylene sulfide polymers.
Arylene sulfide polymers, of which poly(phenylene sulfide) is representative, have unique properties and are being used for an increasing number of applications where physical properties such as electrical insulation, thermal stability and chemical resistance are of importance. Polyarylene sulfide compounds are reported to be useful in a number of applications requiring good impact strength. For example, a number of pump manufacturers are using polyarylene sulfide compounds in sliding vanes, impeller cases, gage guards and seals. Other applications include aircraft and automotive parts, ball valves, pistons, compressor components, gears and gear housings, computer and electronic parts and components, conduits, etc. Due to difficulties in compounding and processing arylene sulfide polymers containing high proportions of fillers, various materials have been disclosed as additives to improve processability. For example, U.S. Pat. No. 4,134,874 discloses the addition of small amounts of ethylene polymers to arylene sulfide polymers to improve processability, but when added at more than about 5 weight percent of the total composition, the ethylene polymers are reported to reduce physical properties of the molding composition including impact strength and flexural modulus. U.S. Pat. No. 3,929,708 discloses the use of silicon fluids such as polysiloxanes of molecular weights of about 500 to 3,000 to improve the processing characteristics of arylene sulfide polymers. The mechanical properties such as tensile strength, elongation and Izod impact strength of the polymers are reportedly not adversely affected by the presence of such silicon fluids in amounts of about 0.05 to 5 weight percent. Several patents, e.g., U.S. Pat. No. 4,337,182, disclose the use of organic silanes in poly(phenylene sulfide) compositions.